Sewage system



Dec. 8, 1970 R. c. Hr-:LKE ET AL i 3,545,011 f sEwAGE SYSTEM Filed Dec. 9, 1968 l 3 Sheets-Sheet 1 62 60 v l0 F16 1 6,' X .f- ,f

ROBERT C. HELKE,

CHARLES E. VANGILDER G 5y MERLIN S.M|LLER IO'/ ATTORNEYS Dec. 8, 1,970 R. c. Hl-:LKE ET AL 3,545,011

SEWAGE SYSTEM med nec. 9, 196e :s sheets-sheet s FIG -7 3v v -l United States Patent O 3,545,011 SEWAGE SYSTEM Robert C. Helke, Dayton, Charles E. Van Gilder, Kettering, and Merlin S. Miller, Bradford, Ohio, assignors to Koehler-Dayton, Inc., Dayton, Ohio, a corporation of Ohio p Filed Dec. 9, 1968, Ser. No. 782,240 Int. Cl. E03d 1/00 U.S. Cl. 4-10 3 Claims ABSTRACT OF THE DISCLOSURE A self-contained, recirculating toilet includes a main holding tank having a drain opening in the bottom thereof and an access opening in the top of the tank in substantially vertically spaced relation to the drain opening. A unitary pump, filter, and drain valve assembly is inserted through the access opening with said drain valve sealing the drain opening when the assembly is locked in place. The drain Valve seal forms part of the -filter and includes an outwardly extending lip which engages the surface of the tank to form one seal, and a circumferentially extending ridge axially spaced from the ridge which engages the inside of the drain opening to form a second seal.

RELATED APPLICATIONS Reference is hereby made to copending application Ser. No. 782,062, filed Dec. 9, 1968, entitled, Flushing Manifold for Portable Toilet, which is assigned to the same assignee as the present invention.

BACKGROUND OF THE INVENTION A need has long existed for portable toilets of suiciently small size and low cost for use in light aircraft, trailers, boats, or in any other environment where a self-contained recirculating toilet system is desired or required by law. Several portable toilet systems have been developed, each including a main holding tank, a toilet bowl which empties into the holding tank, a flushing manifold which surrounds the bowl, a filter, and a pump to draw liquid through the filter from the holding tank and force it into the fiushing manifold. Each of these components in prior art toilets are mounted in separate means, which increases the cost of construction and requires considerable time to disassemble for cleaning and replacement.

SUMMARY OF THE INVENTION This invention relates to an improved self-contained recirculating portable toilet wherein the pump, vfilter and drain valve seal are mounted together as a unitary assembly which may be easily removed when cleaning the toilet. The invention also relates to an improved drain valve seal which is mounted at the lowermost portion of the filter and which engages the drain opening in the main holding tank when the uppermost portion of the assembly rests against the top surface of the main holding tank.

By so constructing the main holding tank that with the access opening located substantially vertically above the drain opening, a single molded member may be used to support a filter, a drain valve, and a pump which may be included within the filter. By dimensioning this unit so that fastening means at its uppermost portion engage the top of the main holding tank when the seal at the bottom of the lter is inserted into the drain opening, the

3,545,011 Patented Dec. 8, 1970 ICC wherein the pump, filter, and drain valve seal are formed on a single member for easy removal for cleaning and lower cost; to provide an improved drain valve having a pa1r of seals to insure that the drain opening is sealed completely when the pump and filter are secured in their operating position, one seal engaging the surface around the drain opening and the other seal engaging the inside surface of the drain opening; and to provide a drain valve which not only seals the drain opening but also functions as an end portion of the filter.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a plan view of the improved self-contained toilet showing the location of the pump motor and the toilet bowl, and also showing in cross section a portion of the flushing manifold which surrounds the toilet bowl;

FIG. 2 is an elevational view of the left side of the toilet shown in FIG. 1 with a check valve and a portion of the inlet hose carrying the cleaning water shown in cross section;

FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. l;

FIG. 4 is a cross-sectional view showing another form of toilet bowl construction;

FIG. 5 is a schematic electrical diagram of the fiushing system including a push button switch, a timer, and the pump motor;

FIG. 6 is a view partly in cross section showing a spray nozzle connected to the inlet hose carrying cleaning water, the spray nozzle being located within the main holding tank;

FIG. 7 is a cross-sectional view of the pump, filter, and seal for the drain opening;

FIG. 8 is an enlarged cross-sectional view of the improved seal showing its configuration prior to its being inserted into the drain opening;

FIG. 9 is an enlarged cross-sectional view showing the configuration of the seal after it has been inserted into the drain opening with its downwardly curved ciroumferentially extending lip engaging the surface of the tank around the drain opening; and

FIG. l0 is an enlarged cross-sectional view showing the configuration of the seal after it has been fully inserted in the drain opening and relative movement has occurred between the seal and the filter.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. l, 2 and 3, the self-contained recirculating toilet of this invention includes a main holding tank 10 which is preferably molded from fiberglass or plastic, having a lower portion |11 in which a drain opening 12 is formed. Hand holds 13 and 14 are formed in the sides of the tank to facilitate handling of the toilet during removal from its operating position. Not shown is the toilet seat and the frame under which the toilet is positioned when in use.

A top 15 for the main holding tank 10, also formed from a single piece of molded fiberglass, is mated and sealed to the main holding tank and has formed therein a toilet bowl .16. A generally horizontal surface 17 surrounds the top of the bowl 16, and an inverted U-shaped member 18 is spaced vertically from this surface to form therewith a flushing manifold 20. The surface 17 is horizontal in the embodiment shown but may also be sloped toward the bowl 16 in order to facilitate draining the fiushing liquid from the manifold. The outer down wardly extending portion of the member 18 engages the outer surface of the bowl 16 in watertight relation. Preferably, the fiberglass 15 is so molded that when the member 18 is mounted in place, a smooth outer surface appearance is created.

The inner downwardly extending portion of the U- shaped member 18 is spaced radially inwardly from the bowl and extends slightly below the top of the surface 17 to form an open slot 21 which extends continuously around the entire periphery of the bowl. Flushing liquid flows into the bowl through an opening 22. As viewed in FIG. 1, flushing liquid will iiow in a clockwise direction and diagonally downwardly across the surface of the bowl 16 to provide the necessary cleaning action. A more detailed explanation of the liushing manifold will be found in the above mentioned application Ser. No. 782,062.

A defiector 23 (FIG. 3) is mounted at the lowermost portion of the bowl on a hinge 24. A pair of outwardly extending nipples 25 cooperate with small holes in the deflector to hold it in place. 'Ihe deflector 23 prevents the viewing of the interior of the main holding tank during normal operation while the hinged construction allows the deflector 23 to be moved out of the way in the event that the fiushing system fails.

In FIG. 4, the toilet bowl -16 is shown formed separate from the top 15. The uppermost portion of the top of the main holding tank includes an integrally formed liange 26 which supports the top surface 17a of the toilet bowl 16. This structure allows the bowl 16 to be formed from plastic or fiberglass having a different color and composition from that used in forming the top 15 and also reduces the cost since a deector 23a may be integrally formed with the bowl.

An access opening 27 (FIG. 7) is provided in the upper horizontal surface 28 of the fiberglass member 15, and this access opening 27 is positioned substantially vertically above the drain opening 12. A member 30 is inserted through the access opening 27 and carries with it a pump motor 31 and a filter 32. A drain seal 35, carried at the lowermost portion of the filter 32, fits into the drain opening 12 when the member 30 is installed.

A flange 36 is formed at the top of the member 30 and carries with it a plurality of fastening means 37, such as the commonly used one-quarter turn fasteners. A gasket 38 between the flange 36 and the upper surface 28 insures that a watertight seal will exist between the member 30 and the upper surface 28 of the main holding tank 410. The length of the member 30 is such that when the ange 36 is locked in place, the seal 35 will also be in its operation position. Guide pins 39 (FIGS. 1 and 2) aid in aligning the member 30 within the opening 27. f

A pump 40 is contained within the member 30 and includes a shaft 41 having an upper end connected to the drive shaft of motor 31 and a lower end connected to an impellerV 43. A cylindrical housing 44 surrounds the impeller 43 and an outlet 45 located at its upper right, as shown in FIG. 7. Thus, filtered liquid will be drawn into the opening in the lower portion of the housing 44 by action of the impeller 43 and forced out through the outlet 45. A hose 46 carries the liquid to a fitting 47, also formed in the flange 36 of the member 30. 'Ihis construction simplies the molding of the member 30, which is a single piece, as described. Referring again to FIG. l, a hose 49 connects the fitting y47 with the inlet 22 of the liushing manifold 20.

The filter 32 consists of a hollow cylindrical member 51 having a plurality of internal axially extending ribs 52. A plurality of slots 53 are cut into the member 51, through which liquid may flow but which are closely spaced to prevent entry of solids particles. The slots are cut clear through the cylindrical member 51 but are not cut through the ribs 52 thus retaining the structural integrity of the filter.

The bottom of the cylindrical member 51 is sealed by flexible resilient member 35, preferably formed from silicon rubber or Neoprene. This fiexible member includes a plurality of flow straightening vanes 55 which cooperate with the cylindrical pump housing 44 to direct filtered liquid into the pump 40.

FIG. 5 is an electrical diagram of the flushing system. A push button switch 57 is mounted to the toilet cover, not shown, and is accessible to those using the toilet. When the push button switch 57 is actuated, a timer 58, physically mounted on the top cover 15, starts and connects a source of electrical power 59 to the pump motor 31 for a period of time, typically in the order of ten seconds, to draw suicient liquid from the main tank 10 through the filter 32 and discharge it through the flushing lmanifold 20 to clean the bowl 16 and the deflector 23.

The toilet of the present invention is provided with means for back fiushing the filter 32 and for cleaning the interior of the tank 10. For the purpose of cleaning, a source of clean water is attached to a fitting 60 shown in FIGS. 1 and 3. A hose 61 .carries this clean water to a spray nozzle 62, shown in cross section in FIG. 6, where it is sprayed into the interior of the tank 10. The spray nozzle includes a rotating head 63 which has an opening 64 on one side thereof to form a jet which causes the head to rotate from the force of the water directed downwardly through the inlet line. The rotating head is held in place by a retaining ring 65 on pin 66.

Clean water also flows through hose 67 into the hose 49 connecting the pump 40 to the flushing manifold 20. A check valve `68 (FIG. 2) prevents any of the flushing liquid from owing backwards through the hose 67 during recirculation of the flushing liquid and therefore prevents contamination of the source of clean water. Also, no liquid from the main tank 10 can be siphoned into the hose 67 since the upper portion of the hose 49 is open to the atmosphere through the flushing manifold 20. Thus, when clean water is forced into the hose 61 this water will fiow through the spray nozzle and into the interior of the tank 10 and also into hose 49 where it will flow upwardly into the flushing manifold 20 and downwardly through the filter 32 in the reverse direction to cause cleaning thereof.

Reference is now made to FIGS. 8 through 10 which show the relationship between the fiexible seal 35, the filter 32, and the drain opening 12 which is formed in the bottom of the tank 10. In FIG. 8, the cylindrical member 51 of the filter 32 is shown as having an outwardly extending lip 70 on which is formed a conically shaped cam surface 71. This outwardly extending lip 70 cooperates with a conically'shaped slot 72 in the seal 35 to hold the seal 35 in place on the filter 32.

The body of the seal 35 has a shape in cross section in a plane parallel to the bottom of the tank 10 which generally corresponds to the shape of and substantially fills the drain opening 12. Preferably, the drain opening is circular. The seal 35 includes an outwardly extending lip 75 which is curved downwardly toward the bottom surface of the tank so that when it engages this surface it will be held tightly against the surface by the resiliency of the material from which the seal 35 is made. The seal 35 also includes an outwardly extending ridge 76 spaced axially downwardly from the lip 75. A `carn surface 72 spaced radially inwardly from the ridge cooperates with the cam surface 71 on the filter 32 so that as the filter is moved downwardly relative to the seal, the seal will expand. The diameter of the ridge 76 is such that, when in the position shown in FIG. 8, it will fit freely into the opening 12.

FIG. 9 shows the seal after it has been inserted into the drain opening but before relative movement occurs between the seal 35 and the filter 32. The outwardly extending lip 75 engages the surface of the tank bottom around the edge of the opening 12, and since this lip is curved downwardly, it forms a first seal. Asv the filter 32 is moved'further downwardly, the filter will move relative to the seal 35 since the seal is now restrained from further movement by the outwardly extending lip 75. Therefore relative motion occurs between the seal 35 and filter 32 which causes the cam surface 71 on the filter 32 to move relative tothe cam surface 72 formed in the seal 35 thus causing the seal to expand forcing the cireumferentially extending ridge 76 into sealing engagement with the interior surface of the opening 12 to form a second seal as shown in FIG. 10. Thus, two sealing surfaces are created, the first between the outwardly extending lip 75 and the bottom surface of the tank 10` which surrounds the opening 12, and the second between the circumferentially extending ridge 76 and the inside surface of the opening 12. The seal 35 and the filter 32 are held in the relative position shown in FIG. l by the fasteners 37 which are received into threaded inserts installed in the top surface 28 of the tank 10.

The seal arrangement thus described allows the easy removal of the seal 35 from the drain opening 12 since, as the filter 32 is moved upwardly relative to the seal, air is permitted to pass between the circumferentially extending ridge 76 and the inside of the drain opening 12 to relieve the vacuum formed in the space 78 between the ridge 76 and the lip 75. Thus, the diameter of the ridge 76 must be carefully controlled, otherwise difficulty may be experienced in removing the seal once it is forced in place.

Since the pump motor 31, the pump 40, the filter 32, and the drain seal 35 are all mounted on the single molded member 30, easy cleaning of this assembly is provided and a reduction in the cost of fabricating a portable toilet of this type is realized.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention.

What is claimed is:

1. A self-contained sewage system including a main holding tank, a toilet bowl emptying into said tank, and a flushing manifold surrounding said bowl;

the improvement comprising:

means forming a drain opening in the bottom of said tank;

means forming an access opening in the top of said tank in substantially vertically spaced relation to said drain opening;

a member removable through said access opening for cleaning including a hollow cylindrically shaped filter positioned at the lower end of said member;

means within said filter to draw liquid thereinto from said tank and to direct said liquid to said iiushing manifold;

a flange at the top of said member;

fastening means on said flange adapted to lock said member to said tank; and

means for closing the lower end of said filter and for sealing said drain opening when said member is inserted into said tank and said fiange is fastened to the top of said tank.

2. The system as defined in claim 1 wherein said filter is cylindrically shaped and includes a plurality of axially spaced and radially extending slots through which liquid may pass.

3. The system as defined in claim 1 wherein said means for sealing said drain opening includes:

a body of resilient material having a shape in cross section in a plane parallel to the bottom of said tank which generally corresponds to the shape of and substantially fills said drain opening;

an outwardly extending lip on said body adapted t0 engage the bottom of said tank around the edge of the drain opening therein in sealing relation;

a circumferentially extending ridge on said body axially spaced from said lip and adapted to fit against the inside of said drain opening when said lip engages the bottom of said tank;

a cam surface in said body spaced radially inwardly from said ridge; and

wherein the lower portion of said filter includes a surface which cooperates with said cam surface for forcing said ridge outwardly into engagement with the inside of said drain opening as said filter is moved downwardly and thus relative to said body after said lip engages the bottom of said tank in sealing relation.

References Cited UNITED STATES PATENTS 3,342,341 9/1967 Lee 4-78 3,454,967 7/1969 Corliss 4-77 WILLIAM I. WYE, Primary Examiner U.S. Cl. X.R. 

